The goals of the Case Western Reserve Teaching Nursing Home Program are to conduct clinical research on specific problems of the elderly,to support this research by centralized administration and recruiting of subjects,to involve long-term care institutions in aging-related research, and to foster the development of such research. The Center Core will be responsible for administration. liaison with nursing home and other sites of subject recruitment, stimulating new research by means of pilot projects and other measures, and quality control. The program will conduct five projects which are related to the Center Core and to the Initial TNH grant In several ways. Part 1, Selected Respiratory and GI Infections of the Elderly will conduct a 3-year survey of the incidence of poorly-understood infections among 500 elderly persons who have different degrees of exposure to other persons. Part 2, Tuberculosis in the Elderly will study immune mechanisms associated with the reportedly Increased incidence and prevalence of this disease in nursing home populations. Part 3 Visual Perception and Alzheimer's Disease will study loss In visual perception among the elderly and explore the possibility that specific loss may serve as an early marker of Alzhelmer's Disease. Part 4, Physiology and Therapy of Sleep Apnea in the Elderly will test the hypothesis that obstructive sleep apnea in the elderly is due to periodic breathing during sleep, rather than to airway narrowing such as has been observed in younger individuals.